Home spirometry is reliable and of consistent quality in children with cystic fibrosis

ABSTRACT

Background: Respiratory management of cystic fibrosis (CF) relies on accurate monitoring of trends in lung function. The COVID-19 pandemic accelerated uptake of home spirometers at our paediatric & adult CF centres. Objectives: To establish the reliability and consistency of home-measured spirometry compared to clinic spirometry in children with CF. Methods: A single centre retrospective study. A timeline was constructed for each individual consisting of 3 pre-pandemic hospital clinic sessions and 3 subsequent virtual sessions. The acceptable period between sessions was 3–12weeks. Remote deviceswere Nuvoair® Next or Spirobank® Smart. Control data from CF adults with concurrent clinic and home Nuvoair® data in 2019. Accepted FVC & FEV1session values were used to calculate coefficient of variance (CoV). Sessions graded as ‘F’ (ATS guidelines) were noted but excluded. GLI percent predicted values were used, with height values interpolated from growth charts if necessary. Results: Sequential spirometry data and baseline demographics are shown in table 1 (n = 139). The proportion of acceptable and unacceptable spirometry (ATS) did not differ between Nuvoair® and hospital measurements. There were more A grades and fewer F grades with hospital spirometry. (Table Presented) Conclusions: Routine home spirometry had acceptable variability and quality compared to hospital measures. The step-up in home spirometry measurements for children using Nuvoair® was not seen in pre-pandemic adult data. The differences between home and hospital measures in children suggest an influence of isolation above that of equipment differences.